Wide-area uniform plasma processing in an ECR plasma

Abstract

Large-area uniform material processing is demonstrated in reactive plasmas produced by a plane antenna with permanent magnets for the electron-cyclotron resonance at 2.45 GHz. Oxygen plasmas are used for the ashing of photoresist films; sulphur hexafluoride and carbon tetrafluoride are used for the etching of polysilicon and silicon dioxide films, respectively. In both cases the plasma parameters are measured in detail. Typically, the electron density in and plasmas is about (1 - 2) and the electron temperature is about 3 eV for a microwave power of 600 W. However, in the plasma. The ashing and etching rates for photoresist and polysilicon are 40 - 50 and the etching rate of silicon dioxide is about 10 in the uniform plasma region (z = 25 - 35 cm), when the microwave power is 600 W under the condition of the floating substrate potential. A quite homogeneous material processing of those films is established over a diameter of 40 - 45 cm at the distance of 25 - 35 cm from the antenna.